Polymer dispersion

Abstract

The present invention generally relates to a dispersion comprising a plurality of core-shell particles, wherein the core comprising non-fluorinated polymer and the shell comprises fluorinated polymer. It also relates to the use of the said dispersion as an additive in a coating formulation in at least 10 wt %, wherein substrates coated with said coating formulation exhibit improved solar-reflective and anti-dirt properties. In preferred embodiments, the said core comprises methyl methacrylate monomer and the said shell comprises hexafluorobutyl acrylate, hexafluorobutyl methacrylate, tridecafluorooctyl arylate or perfluorooctyl acrylate.

1 . A dispersion comprising
 a. a plurality of core-shell particles, wherein the core comprises at least one non-fluorinated polymer and the shell comprises at least one shell layer having at least one fluorinated polymer or fluorinated copolymer therein; and   b. a solvent;   wherein said dispersion has a solid content of the core-shell particles of at least 10 wt %.   
     
     
         2 . The dispersion of  claim 1 , wherein said shell comprises a fluorinated copolymer of at least two fluorinated monomers in the same shell layer. 
     
     
         3 . The dispersion of  claim 1 , wherein said fluorinated polymer or fluorinated copolymer comprises a fluoroalkyl monomer with at least one of an acrylate monomer or a methacrylate monomer, or mixtures thereof. 
     
     
         4 . The dispersion of  claim 3 , wherein said fluorinated polymer is selected from the group consisting of poly(2,2,2-Trifluoroethyl Acrylate), poly(2,2,2-Trifluoroethyl Methacrylate), poly(2,2,3,3-Tetrafluoropropyl Acrylate), poly(2,2,3,3-Tetrafluoropropyl Methacrylate), poly(2,2,2,3,3-Pentafluoropropyl Acrylate, poly(2,2,2,3,3-Pentafluoropropyl Methacrylate, poly(2,2,3,4,4,4-Hexafluorobutyl Acrylate), poly(2,2,3,4,4,4-Hexafluorobutyl Methacrylate), poly(2,2,3,3,4,4,4-Heptafluorobutyl Acrylate), poly(2,2,3,3,4,4,4-Heptafluorobutyl Methacrylate), poly(2,2,3,3,4,4,5,5-Octafluoropentyl Acrylate), poly(2,2,3,3,4,4,5,5-Octafluoropentyl Methacrylate), poly(3,3,4,4,5,5,6,6,7,7,8,8,8-Tridecafluorooctyl Acrylate), poly(3,3,4,4,5,5,6,6,7,7,8,8,8-Tridecafluorooctyl Methacrylate), poly(1H,1H-Perfluorooctyl Acrylate), poly(1H,1H-Perfluorooctyl Methacrylate) poly(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-Heptadecafluorodecyl Acrylate), poly(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-Heptadecafluorodecyl Methacrylate), poly(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-Heneicosafluorododecyl Acrylate), poly(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-Heneicosafluorododecyl Methacrylate, and mixtures thereof. 
     
     
         5 . The dispersion of  claim 3 , wherein said fluorinated copolymer comprises at least two monomers selected from the group consisting of 2,2,3,4,4,4-Hexafluorobutyl Acrylate, 2,2,3,4,4,4-Hexafluorobutyl Methacrylate, 3,3,4,4,5,5,6,6,7,7,8,8,8-Tridecafluorooctyl Acrylate, 3,3,4,4,5,5,6,6,7,7,8,8,8-Tridecafluorooctyl Methacrylate, 1H,1H-Perfluorooctyl Acrylate, and 1H,1H-Perfluorooctyl Methacrylate. 
     
     
         6 . The dispersion of  claim 1 , wherein the solvent is an aqueous solvent. 
     
     
         7 . The dispersion of  claim 1 , wherein the core-shell particles have an average particle size in the range of 50 nm to 800 nm. 
     
     
         8 . The dispersion of  claim 1 , wherein the core-shell particles have an average shell thickness in the range of 5 nm to 50 nm. 
     
     
         9 . The dispersion of  claim 1 , wherein the solid content of the dispersion is in the range of 35% to 60%. 
     
     
         10 .- 19 . (canceled) 
     
     
         20 . A method of increasing total solar reflectance (TSR) of a substrate comprising the step of forming a coating of a mixture of a dispersion with a coating material on a surface of said substrate, wherein said dispersion comprises a solvent with a plurality of core-shell particles disposed therein, said core-shell particles having at least one non-fluorinated polymer in the core and at least one fluorinated polymer or fluorinated copolymer in at least one shell layer of the shell, and said core-shell particles forming a solid content of at least 10% of the dispersion. 
     
     
         21 . The method of  claim 20 , wherein said coating has a thickness in the range of 50 nm to 500 μm. 
     
     
         22 . The method of  claim 20 , further comprising the step of heat treating the coating. 
     
     
         23 . The method of  claim 20 , wherein the coating formed on the substrate is capable of repelling dirt. 
     
     
         24 . A coated article comprising a layer of a dispersion coated thereon, said dispersion comprises a solvent with a plurality of core-shell particles disposed therein, said core-shell particles having at least one non-fluorinated polymer in the core and at least one fluorinated polymer or fluorinated copolymer in at least one shell layer of the shell, and said core-shell particles forming a solid content of at least 10% of the dispersion. 
     
     
         25 . The coated article of  claim 24 , wherein said coated article is capable of reflecting solar light and repelling dirt.